This argument relies on a highly controversial principle about how an explanation of why something is a value must work — a very similar principle to that which was appealed to in the argument that intrinsic value must be an intrinsic property [section 2.1.1]. If this principle is false, then an explanatory theory of why both pleasure and knowledge are values can be offered which does not work by subsuming them under a further, more fundamental value. Reductive theories of what it is to be a val